/* 变灰 
html {
filter: grayscale(100%);
-webkit-filter: grayscale(100%);
-moz-filter: grayscale(100%);
-ms-filter: grayscale(100%);
-o-filter: grayscale(100%);
filter: url(desaturate.svg#grayscale);filter:progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);-webkit-filter: grayscale(1);}
body{filter:gray;}
html {FILTER: progid:DXImageTransform.Microsoft.BasicImage(grayscale=1); -webkit-filter: grayscale(1); -moz-filter: grayscale(100%); -ms-filter: grayscale(100%); -o-filter: grayscale(100%);BACKGROUND: #fff; COLOR: #000}
BODY,DIV,DL,DT,DD,UL,OL,LI,H1,H2,H3,H4,H5,H6,PRE,CODE,FORM,FIELDSET,LEGEND,INPUT,TEXTAREA,P,BLOCKQUOTE,TH,TD{FILTER: gray; } 
*/